3.3.2.26. NXxas

Status:

application definition, extends NXobject

Description:

This is an application definition for raw data from an X-ray absorption spectroscopy experiment.

This is essentially a scan on energy versus incoming/ absorbed beam.

Symbols:

The symbol(s) listed here will be used below to coordinate datasets with the same shape.

nP: Number of points

Groups cited:

NXdata, NXdetector, NXentry, NXinstrument, NXmonitor, NXmonochromator, NXsample, NXsource

Structure:

ENTRY: (required) NXentry

@entry: (required) NX_CHAR

NeXus convention is to use “entry1”, “entry2”, … for analysis software to locate each entry.

title: (required) NX_CHAR

start_time: (required) NX_DATE_TIME

definition: (required) NX_CHAR

Official NeXus NXDL schema to which this file conforms

Obligatory value: NXxas

INSTRUMENT: (required) NXinstrument

SOURCE: (required) NXsource

type: (required) NX_CHAR

name: (required) NX_CHAR

probe: (required) NX_CHAR

Obligatory value: x-ray

monochromator: (required) NXmonochromator

energy: (required) NX_FLOAT (Rank: 1, Dimensions: [nP])

incoming_beam: (required) NXdetector

data: (required) NX_NUMBER (Rank: 1, Dimensions: [nP])

absorbed_beam: (required) NXdetector

data: (required) NX_NUMBER (Rank: 1, Dimensions: [nP])

This data corresponds to the sample signal.

SAMPLE: (required) NXsample

name: (required) NX_CHAR

Descriptive name of sample

MONITOR: (required) NXmonitor

mode: (required) NX_CHAR

Count to a preset value based on either clock time (timer) or received monitor counts (monitor).

Any of these values: monitor | timer

preset: (required) NX_FLOAT

preset value for time or monitor

data: (required) NX_NUMBER (Rank: 1, Dimensions: [nP])

This field could be a link to /NXentry/NXinstrument/incoming_beam:NXdetector/data

DATA: (required) NXdata

mode: (required) NX_CHAR

Detection method used for observing the sample absorption (pick one from the enumerated list and spell exactly)

Any of these values:

  • Total Electron Yield

  • Partial Electron Yield

  • Auger Electron Yield

  • Fluorescence Yield

  • Transmission

energy: link (suggested target: /NXentry/NXinstrument/monochromator:NXmonochromator/energy)

absorbed_beam: link (suggested target: /NXentry/NXinstrument/absorbed_beam:NXdetector/data)

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/applications/NXxas.nxdl.xml